<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>选择</title>

    <script>
        onload = function () {
            //给第一个复选框单击事件
            document.getElementById("firstCb").onclick = function () {
                //获取复选框的checkbox属性
                let flag = this.checked;
                //获取其他复选框
                let arr = document.getElementsByClassName("itemSelect");
                for (let i = 0; i < arr.length ; i++) {
                    arr[i].checked = flag;
                }
            }
        }
    </script>


</head>
<body>

<table id="tab1" border="1" width="800" align="center" >
    <tr>
        <td colspan="5"><input type="button" value="删除"></td>
    </tr>
    <tr>
        <th><input type="checkbox" id="firstCb" onclick="checkAll(this)"></th>
        <th>分类ID</th>
        <th>分类名称</th>
        <th>分类描述</th>
        <th>操作</th>
    </tr>
    <tr>
        <td><input type="checkbox" class="itemSelect"></td>
        <td>1</td>
        <td>手机数码</td>
        <td>手机数码类商品</td>
        <td><a href="">修改</a>|<a href="">删除</a></td>
    </tr>
    <tr>
        <td><input type="checkbox" class="itemSelect"></td>
        <td>2</td>
        <td>电脑办公</td>
        <td>电脑办公类商品</td>
        <td><a href="">修改</a>|<a href="">删除</a></td>
    </tr>
    <tr>
        <td><input type="checkbox" class="itemSelect"></td>
        <td>3</td>
        <td>鞋靴箱包</td>
        <td>鞋靴箱包类商品</td>
        <td><a href="">修改</a>|<a href="">删除</a></td>
    </tr>
    <tr>
        <td><input type="checkbox" class="itemSelect"></td>
        <td>4</td>
        <td>家居饰品</td>
        <td>家居饰品类商品</td>
        <td><a href="">修改</a>|<a href="">删除</a></td>
    </tr>
</table>

</body>
</html>